Comparison of computed tomography and microradiography for graft evaluation after reconstruction of critical size bone defects using β-tricalcium phosphate

Bone defects introduced by accidents or diseases are very painful for the patient and their treatment leads to high expenses for the healthcare systems. When a bone defect reaches a critical size, the body is not able to restore this defect by itself. In this case a bone graft is required, either an autologous one taken from the patient or an artificial one made of a bioceramic material such as calcium phosphate. In this study β-tricalcium phosphate (β-TCP) was dispersed in a polymer matrix containing poly(lactic acid) (PLA) and poly(ethylene glycole) (PEG). These compounds were extruded to filaments, which were used for 3D printing of cylindrical scaffolds via Fused Deposition of Ceramics (FDC) technique. After shaping, the printed parts were debindered and sintered. The components combined macro- and micropores with a pore size of 1 mm and 0.01 mm, respectively, which are considered beneficial for bone healing. The compressive strength of sintered cylindrical scaffolds exceeded 72 MPa at an open porosity of 35%. The FDC approach seems promising for manufacturing patient specific bioceramic bone grafts.

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Mesenchymal stem cells and porous β-tricalcium phosphate composites prepared through stem cell screen-enrich-combine(−biomaterials) circulating system for the repair of critical size bone defects in goat tibia

Stem Cell Research & Therapy ◽

10.1186/s13287-018-0906-1 ◽

2018 ◽

Vol 9 (1) ◽

Cited By ~ 9

Author(s):

Wenxiang Chu ◽

Yaokai Gan ◽

Yifu Zhuang ◽

Xin Wang ◽

Jie Zhao ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Stem Cell ◽

Tricalcium Phosphate ◽

Critical Size ◽

Bone Defects

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Faculty Opinions recommendation of In vivo investigation of tissue-engineered periosteum for the repair of allogeneic critical size bone defects in rabbits.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.727723479.793545144 ◽

2018 ◽

Author(s):

Warren Grayson

Keyword(s):

Critical Size ◽

Bone Defects

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The preparation and application of calcium phosphate biomedical composites in filling of weight-bearing bone defects

Scientific Reports ◽

10.1038/s41598-021-83941-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lijia Cheng ◽

Tianchang Lin ◽

Ahmad Taha Khalaf ◽

Yamei Zhang ◽

Hongyan He ◽

...

Keyword(s):

Mechanical Properties ◽

Calcium Phosphate ◽

Tricalcium Phosphate ◽

Weight Bearing ◽

Bone Defects ◽

Type I ◽

Artificial Bone ◽

Thermosensitive Hydrogel ◽

Bone Repairing ◽

Histological Staining

AbstractNowadays, artificial bone materials have been widely applied in the filling of non-weight bearing bone defects, but scarcely ever in weight-bearing bone defects. This study aims to develop an artificial bone with excellent mechanical properties and good osteogenic capability. Firstly, the collagen-thermosensitive hydrogel-calcium phosphate (CTC) composites were prepared as follows: dissolving thermosensitive hydrogel at 4 °C, then mixing with type I collagen as well as tricalcium phosphate (CaP) powder, and moulding the composites at 37 °C. Next, the CTC composites were subjected to evaluate for their chemical composition, micro morphology, pore size, Shore durometer, porosity and water absorption ability. Following this, the CTC composites were implanted into the muscle of mice while the 70% hydroxyapatite/30% β-tricalcium phosphate (HA/TCP) biomaterials were set as the control group; 8 weeks later, the osteoinductive abilities of biomaterials were detected by histological staining. Finally, the CTC and HA/TCP biomaterials were used to fill the large segments of tibia defects in mice. The bone repairing and load-bearing abilities of materials were evaluated by histological staining, X-ray and micro-CT at week 8. Both the CTC and HA/TCP biomaterials could induce ectopic bone formation in mice; however, the CTC composites tended to produce larger areas of bone and bone marrow tissues than HA/TCP. Simultaneously, bone-repairing experiments showed that HA/TCP biomaterials were easily crushed or pushed out by new bone growth as the material has a poor hardness. In comparison, the CTC composites could be replaced gradually by newly formed bone and repair larger segments of bone defects. The CTC composites trialled in this study have better mechanical properties, osteoinductivity and weight-bearing capacity than HA/TCP. The CTC composites provide an experimental foundation for the synthesis of artificial bone and a new option for orthopedic patients.

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Comparison of the different voxel sizes in the estimation of peri-implant fenestration defects using cone beam computed tomography: an ex vivo study

International Journal of Implant Dentistry ◽

10.1186/s40729-020-00254-2 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Mehmet Hakan Kurt ◽

Nilsun Bağış ◽

Cengiz Evli ◽

Cemal Atakan ◽

Kaan Orhan

Keyword(s):

Computed Tomography ◽

Cone Beam Computed Tomography ◽

Ex Vivo ◽

Statistical Significance ◽

Area Under The Curve ◽

Titanium Implant ◽

Bone Defects ◽

Titanium Implants ◽

Cone Beam ◽

Voxel Size

Abstract Background To examine the influence of voxel sizes to detect of peri-implant fenestration defects on cone beam computed tomography (CBCT) images. Materials and methods This study performed with three sheep heads both maxilla and mandible and two types of dental implant type 1 zirconium implant (Zr40) (n = 6) and type 2 titanium implant (Ti22) (n = 10). A total of 14 peri-implant fenestrations (8 buccal surfaces, 6 palatal/lingual surface) were created while 18 surfaces (8 buccal, 10 palatal/lingual) were free of fenestrations. Three observers have evaluated the images of fenestration at each site. Images obtained with 0.75 mm3, 0.100 mm3, 0.150 mm3, 0.200 mm3, and 0.400 mm3 voxel sizes. For intra- and inter-observer agreements for each voxel size, Kappa coefficients were calculated. Results Intra- and inter-observer kappa values were the highest for 0.150 mm3, and the lowest in 0.75 mm3 and 0.400 mm3 voxel sizes for all types of implants. The highest area under the curve (AUC) values were found higher for the scan mode of 0.150 mm3, whereas lower AUC values were found for the voxel size for 0.400 mm3. Titanium implants had higher AUC values than zirconium with the statistical significance for all voxel sizes (p ≤ 0.05). Conclusion A voxel size of 0.150 mm3 can be used to detect peri-implant fenestration bone defects. CBCT is the most reliable diagnostic tool for peri-implant fenestration bone defects.

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Role of Autologous Platelet Gel (APG) in Bone Healing: A Rabbit Study

Applied Sciences ◽

10.3390/app11010395 ◽

2021 ◽

Vol 11 (1) ◽

pp. 395

Author(s):

Antonio Scarano ◽

Francesco Inchingolo ◽

Biagio Rapone ◽

Alberta Greco Lucchina ◽

Erda Qorri ◽

...

Keyword(s):

Critical Size ◽

Bone Defects ◽

New Bone Formation ◽

Platelet Gel ◽

Woven Bone ◽

Rapid Healing ◽

Rabbit Bone ◽

Autologous Platelet ◽

New Zealand Rabbits

Purpose: The aim of the present study is to evaluate the influence and efficacy of autologous platelets on bone regeneration in a rabbit defects model. Materials and Methods: A total of 12 critical size tibial defects were produced in six New Zealand rabbits: A total of six defects were filled with autologous platelet gel (APG) and six defects were maintained as untreated controls. No membranes were used to cover the bone osteotomies. The histology and histomorphometry were performed at four weeks on retrieved samples of both groups. Results: No complications were reported in any of the animals nor for the defects produced. A significantly higher lamellar and woven bone percentage was reported for the APG group with a lower level of marrow spaces (p < 0.05). Evidence of newly formed bone was found in the superficial portion of the bone defect of APG samples where no aspects of bone resorption were observed. Conclusions: The evidence of the present research revealed that APG increases new bone formation restricted to the cortical portion and induces more rapid healing in rabbit bone defects than in untreated defects.

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Personalized medicine for reconstruction of critical-size bone defects – a translational approach with customizable vascularized bone tissue

npj Regenerative Medicine ◽

10.1038/s41536-021-00158-8 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Annika Kengelbach-Weigand ◽

Carolina Thielen ◽

Tobias Bäuerle ◽

Rebekka Götzl ◽

Thomas Gerber ◽

...

Keyword(s):

Personalized Medicine ◽

Large Scale ◽

Critical Size ◽

Therapeutic Option ◽

Living Organism ◽

Bone Defects ◽

Sheep Model ◽

Simple Alternative ◽

Translational Approach ◽

Near Future

AbstractTissue engineering principles allow the generation of functional tissues for biomedical applications. Reconstruction of large-scale bone defects with tissue-engineered bone has still not entered the clinical routine. In the present study, a bone substitute in combination with mesenchymal stem cells (MSC) and endothelial progenitor cells (EPC) with or without growth factors BMP-2 and VEGF-A was prevascularized by an arteriovenous (AV) loop and transplanted into a critical-size tibia defect in the sheep model. With 3D imaging and immunohistochemistry, we could show that this approach is a feasible and simple alternative to the current clinical therapeutic option. This study serves as proof of concept for using large-scale transplantable, vascularized, and customizable bone, generated in a living organism for the reconstruction of load-bearing bone defects, individually tailored to the patient’s needs. With this approach in personalized medicine for the reconstruction of critical-size bone defects, regeneration of parts of the human body will become possible in the near future.

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Longitudinal in vivo evaluation of bone regeneration by combined measurement of multi-pinhole SPECT and micro-CT for tissue engineering

Scientific Reports ◽

10.1038/srep10238 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 16

Author(s):

Philipp S. Lienemann ◽

Stéphanie Metzger ◽

Anna-Sofia Kiveliö ◽

Alain Blanc ◽

Panagiota Papageorgiou ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Bone Formation ◽

Bone Regeneration ◽

Bone Defects ◽

Histological Evaluation ◽

Biological Processes ◽

Micro Ct ◽

Pinhole Spect

Abstract Over the last decades, great strides were made in the development of novel implants for the treatment of bone defects. The increasing versatility and complexity of these implant designs request for concurrent advances in means to assess in vivo the course of induced bone formation in preclinical models. Since its discovery, micro-computed tomography (micro-CT) has excelled as powerful high-resolution technique for non-invasive assessment of newly formed bone tissue. However, micro-CT fails to provide spatiotemporal information on biological processes ongoing during bone regeneration. Conversely, due to the versatile applicability and cost-effectiveness, single photon emission computed tomography (SPECT) would be an ideal technique for assessing such biological processes with high sensitivity and for nuclear imaging comparably high resolution (<1 mm). Herein, we employ modular designed poly(ethylene glycol)-based hydrogels that release bone morphogenetic protein to guide the healing of critical sized calvarial bone defects. By combined in vivo longitudinal multi-pinhole SPECT and micro-CT evaluations we determine the spatiotemporal course of bone formation and remodeling within this synthetic hydrogel implant. End point evaluations by high resolution micro-CT and histological evaluation confirm the value of this approach to follow and optimize bone-inducing biomaterials.

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